The lowest number of any step in your sound processing setup will always be the maximum output.
If your sound passes through FxSound and then goes to your speakers, it will be 24bit 48kHz (if the file you are playing supports it), but never more.
If you can let your sound go directly to your speakers, you will be able to get 24bit 192kHz as your maximum output (if the file you are playing supports it).
There, I hope that answers your question.
EDIT: Forgot to push the “Reply to” button.